底泥疏浚对温州市牛桥底河水环境质量的影响

Impact of dredging on water quality of Niuqiaodi River in Wenzhou

以温州市牛桥底河为研究对象,对河道疏浚前、中、后水体中理化指标、重金属含量及生物毒性进行跟踪分析.结果表明,牛桥底河底泥疏浚显著降低了水中的CODCr浓度,提高了DO含量和透明度.疏浚工程实施后,水中NH+4-N、TN、TP及重金属含量呈现"先升高,后降低"的变化趋势.疏浚不同阶段牛桥底河水样对发光细菌和胚胎的生物毒性先增强后逐渐减弱,总体上,疏浚有助于减轻水样的生物毒性.相关性分析表明水样的生物毒性与TN相关性显著,与重金属相关性不大.

The physicochemical factors,heavy metals and biological toxicity in water sample before,during and after dredging of Niuqiaodi River in Wenzhou were investigated.The result showed that after the sediment dredging of Niuqiaodi River,the CODCrconcentration in water sample was significantly reduced,while the DO content and transparency were enhanced.The contents of NH＋4-N,TN,TP and heavy metals in water sample were firstly increased and then decreased.Both the Luminescent bacteria and Xenopus tropicalis embryos tests indicated the toxicity of water sample firstly weakened,then enhanced in different stages of dredging.Generally speaking,sediment dredging was helpful to alleviate the toxicity of water sample.The correlation analysis showed the toxicity of water sample was significantly related to TN content andhad little relationship with heavy metals.